Department of Chemistry and Biochemistry (Conference/Workshop/Seminar)

John B. Asbury, Department of Chemistry, The Pennsylvania State University, University Park, PA, will present a seminar entitled, "Quantum Confinement, Materials and Molecules: Pathways to High Efficiency Solution Processable Solar Cells".
*
Everyone is welcome!
*
Abstract:
Many emerging electronic materials targeting high throughput low temperature processing are molecular in nature. Examples include solution processable organic and colloidal quantum dot materials for photovoltaic and flexible display technologies. The Asbury group has pioneered the development of ultrafast vibrational spectroscopy techniques to examine electronic processes in materials with particular focus on the influence that underlying molecular structures have on those properties.

This seminar will focus on understanding the influence that ligands have on the efficiency of colloidal quantum dot (CQD) photovoltaic materials. CQDs are rapidly emerging as a third generation photovoltaic technology that promises a solution processable equivalent to silicon solar cells. They combine bandgap tunability to capture all of the solar spectrum with large area solution processability for low cost hight speed manufacture. Like traditional inorganic semiconductors, for which understanding the mechanisms of charge transport was critical to such advances as modern computing and solar cell technologies, progress in CQD photovoltaic efficiency has occurred through development of methods to control charge transport. The mechanism of charge transport in colloidal quantum dot solids has, until now, been controversial. Using ultrafast vibrational spectroscopy in partnership with leaders in the CQD photovoltaic field, we have identified the nature of electrical transport states that are principally responsible for charge transport in CQD solids and elucidated the role that ligands have in determining the properties of these states. Insights from the findings provide new understanding of current limitations and give direction to ongoing efforts to realize yet higher efficiency CQD solar cells.